Boiler



Oct. 3, 1933. P, AUGUSTIN-NORMAND' BOILER 2 v sheem-sneetI 1 Filed ril 27, 1951 Ocut.` l3,4 1933. P. AuGu'rlN-NORMAND 1,923,981

BOILER I 2 Sheets-sheet' 2 Filed April 2 El g- H f Patented Oct. 3, 1933 BOILER Paul Augustin-Normand, Le Havre, France, as-

signor to Socit Anonyme Chantiers et Ateliers Augustin Normand, Le Havre, France Application April 27, 1931, Serial No. 533,330, and in France February 16, 1931 Claims. (Cl. 122-236) The present invention relates to new arrangements of express water-tube boilers with one upper steam and water drum and one lower water drum, comprising two combustion chambers, 5 which are bounded on one side by the main heating surface, heated chiefly by convection and located almost vertically so as to further thecirculation, and which are wholly surrounded on zthe other side by evaporating tubes outwardly curved and heated solely by radiation so as to prevent the loss of the heat radiating laterally and towards the lower part of the boiler.

The arrangements proposed by the present ingvention also propose the possible use of superating tubes constituting the main heating surface at suitable places which depend upon the amount of superheat which it is wished to obtain. Suitable baliles allow of directing the path of the gases if this benecessary so that said gases may follow a predetermined path, which however can vary according to the proposed arrangements. Thus it is possible to propose a single or double longitudinal circulation with frame-return, or a vertical circulation. The bailles can be constituted only by tubes, which then are touching, or in any other way.

The accompanying drawings show by way of example three constructions' according to the invention.

Fig. l shows a section of the nest of tubes of a b`il'r made at right angles to. the axes of the drums. l.

Fig. 2 is a section on the line A-A of Fig. 1 and shows that the gases follow a single longitudinal path.

Fig. 3 is another section on the line AA of Fig. 1 and vshows that the gases follow a double longitudinal path instead of following a single longitudinal path as in the case of Fig. 2.

Fig. 4 is a half-section corresponding to'the case in which a vertical path for. the gases is adopted. v

Fig. 5 is similar to Fig. 4 but shows a smallV longitudinal sheet-iron baille arranged in the top of the principal nest. l

Fig. 6 shows a hollow brickwork, Fig. '7 shows a brickwork provided inside with water tubes.

Fig. 8 shows a brickwork protected on its inner face with water tubes; and

Fig. 9 shows a mechanical device for intensifying the circulation of water.

In the arrangement which is shown in Fig. l, all the evaporating tubes connect an upper steam 'heater nests of tubes located among the evaporand water drum 1 to a lower water drum 2; the greater part of these tubes constitutes the central nest 3, which are arranged in spaced vertical columns and traversed by the hot gases, whilst some tubes 4 bound the combustion chambers 60 externally overthe remainder of their circuit, these tubes being heated by radiation alone and preventing, as already stated, the loss of heat not only laterally'but also by the lower part of the boiler. A superheater nest of tubes 5 can be 55 inserted vertically between the columns of the central nest between two lower and upper steam drums 6 and 7. The gases can follow a longitudinal path either single or double and, in the case of the double longitudinal path, the size of section to be given respectively to the two parts of the central nest of evaporating and superheating tubes, that is to say to the parts traversed by the gases in different directions, should be calculated in such way as to allow for the' normal 75 flow, through the second part, of the bulkof the gases which has traversed the rst part, taking into account the decrease in volume of this'bulk owing to its cooling. The rst part of the central nest can then be constituted by the evaporating tubes 3, whilst the second part can be constituted, either on its whole length or on part of its length, by the superheater tubes 5. It is scarcely neces- .sary to state that, with equal intensity of combustion, the single longitudinal path will ensure being obtained by means of bafes 9 and 10 con- 95 sisting of the touching tubes of the nest 3, the baliles 9 separating the combustion chambers` from the rst parts of the central nest and being located to the front, whilst the baliles 10 separate the first parts of the central nest from the second part and are located only to the back.

In the case of Figs. 2 and 3, the external row of the peripheral nest has been shown touching,

the better toprotect the shell" from radiation 105 from the furnace.

In the arrangement shown in Fig. 4, the evaporating tubes all connect the upper steam and water chamber 1 to the lower water vessel 2, as in the case of Fig. 1, but the gases are constrained to follow a transverse path, the gases entering the zentral nest at the lower part and leaving it at the upper part. The combustion chamber and the central heating surface are separated in the upper region by a baille of touching tubes so that the hot gases cannot pass directly from the combustion chamber to the smoke-box, and must follow the path indicated by the arrows in Fig. 4. A small longitudinal packing of sheet-iron, asbestos or any arrangement of fire proof material 12 (Fig. 5) can moreover be arranged in the top of the principal nest, where it meets each of the peripheral nests, so as to prevent the gases from passing through the gaps between the tubes, which there no longer vao It is to be clearly understood that the examples of construction described above and shown in the accompanying drawings are not of a limiting character and that various modifications may be introduced without exceeding the yscope of the invention.. More particularly, thesha'pe of the superheater may be different. The bailies which direct the path of the gases, instead of being constituted by touching tubes forming part ofl r an evaporati'ng nest, may b'e constituted by an assemblage of tubes and blocks or plates of metal, by an assemblage of tubes and brickwork, by brickwork alone or finally by sheets or plates of refractory or inoxidizable materials; each time that a baiiie is provided at the side of the furnace, it may be built, either at the flrstrow of the nest or at a row further back towards the interior of this nest (for example the second or third) if it be wished to expose a bigger heating surface to the radiant heat.

Instead of lbeing plain, the brickwork 1.5 at the ends may be hollow (Fig. 6'), or provided inside with water tubes 13 (Fig. 7), or protected b y same 14 (Figs. 5 and 8). The boiler arrangements proposed are adapted for a double-ended arrangement, that is to say, in which two identical boilers are connected together by their back 8 ends. It is to be noted that the arrangements proposed are equally applicable to firing with ordinary coal, with pulverized coal or with liquid or gaseous fuel.

It is obvious that all the boilers of which the 8 arrangement of the nests of tubes has been stated may be furnished with downcomer tubes 16 outside the'furnace and that the circulation in these tubes may be intensified by means of mechanical devices 17 (Fig. 9), and, on the other hand, all 9 these boilers may be completed by the addition of feed water heaters and air-heaters.

What is claimed,

1. An express water-tube boiler comprising a single upper drum, a single receiver drum, a mainl 9 heating surface in the form of tubes arranged between the drums and positioned in a substantial vertical direction, two combustion chambers arranged on opposite sides o f the main heating surface, auxiliary heating surfaces consisting of 1U a singleA range of tubes surrounding the outer sides of the two combustion chambers and heated only by radiation and means for conducting the heating gases from the two combustion chambers through the main heating surface substantially '1U in all parts of said main heating surface.

2. An express water-tube boiler as claimed in claim 1, wherein means are provided to cause the gases to follow a single path. v

3. An express water-tube boiler asclaimed in 11 claim 1, wherein means is provided to cause the 

